Helicobacter pylori Outer Membrane Vesicles Engage TLR2 Through NapA to Promote Epithelial Association and Inflammatory Signalling
- 1Laboratorio de Carcinogénesis Molecular, Instituto de Investigación y DoctoradosUniversidad Central de ChileSantiago Chile
- 2Centro Interdisciplinario de Investigación Biomédica e Ingeniería para la Salud (MEDING), Facultad de Medicina, Campus de la Salud Universidad de Valparaíso Viña del Mar Chile
- 3Dirección de Investigación Universidad Bernardo O'Higgins Santiago Chile
Abstract
Helicobacter pylori infection is characterized by chronic gastric inflammation driven by persistent activation of innate immune signaling pathways. Outer membrane vesicles (OMVs) released by H. pylori are important mediators of host–pathogen interactions. Although several mechanisms of OMV internalization have been described, how specific OMV‐associated bacterial factors engage host innate immune receptors and couple vesicle association to inflammatory signaling remains poorly understood. Here, we investigated the contribution of OMV‐associated virulence factors and Toll‐like receptor 2 (TLR2) heterodimers to OMV–host cell interactions in gastric epithelial cells. Using engineered AGS and GES‐1 reporter cells expressing TLR2/1 or TLR2/6, together with genetically defined OMVs, we found that H. pylori OMVs preferentially associated with TLR2‐expressing cells and induced robust NF‐κB activation. Comparative analysis of OMVs from wild‐type and isogenic mutant strains identified Neutrophil‐Activating Protein A (NapA) as a major determinant of TLR2‐dependent OMV association and inflammatory signaling, whereas urease had a more limited contribution. Disruption of NapA or neutralization of TLR2 markedly reduced OMV association with gastric epithelial cells. Purified H. pylori lipopolysaccharide elicited a comparatively weak and TLR2/6‐biased response, indicating that it does not account for the robust TLR2‐dependent signaling induced by intact OMVs. Furthermore, OMV‐associated NapA exhibited greater pro‐inflammatory activity than soluble recombinant NapA, supporting a role for the vesicular context in enhancing TLR2‐dependent signaling. Pharmacological inhibition with sulforaphane significantly attenuated OMV‐induced TLR2/NF‐κB activation. Collectively, these findings identify a previously unrecognized role for OMV‐associated NapA in linking TLR2‐dependent vesicle association with gastric epithelial cells to inflammatory signaling and support a model in which vesicular presentation of bacterial factors contributes to innate immune receptor engagement, providing a mechanistic link between the initial OMV–host cell interaction and subsequent inflammatory signalling.
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BibTeX
@article{rubilar2026helicobacter,
title = {{Helicobacter pylori Outer Membrane Vesicles Engage TLR2 Through NapA to Promote Epithelial Association and Inflammatory Signalling}},
author = {Mariaignacia Rubilar and Rosy Brito and Annegrett Palavecino and Joan Villena and Marco Mellado and María I. Silva and Manuel Valenzuela‐Valderrama},
journal = {Journal of Extracellular Vesicles},
year = {2026},
month = oct,
doi = {10.1002/jev2.70376},
url = {https://doi.org/10.1002/jev2.70376},
note = {CC BY},
}
RIS
TY - JOUR
TI - Helicobacter pylori Outer Membrane Vesicles Engage TLR2 Through NapA to Promote Epithelial Association and Inflammatory Signalling
AU - Mariaignacia Rubilar
AU - Rosy Brito
AU - Annegrett Palavecino
AU - Joan Villena
AU - Marco Mellado
AU - María I. Silva
AU - Manuel Valenzuela‐Valderrama
PY - 2026
DA - 2026/10/26
JO - Journal of Extracellular Vesicles
DO - 10.1002/jev2.70376
UR - https://doi.org/10.1002/jev2.70376
AB - Helicobacter pylori infection is characterized by chronic gastric inflammation driven by persistent activation of innate immune signaling pathways. Outer membrane vesicles (OMVs) released by H. pylori are important mediators of host–pathogen interactions. Although several mechanisms of OMV internalization have been described, how specific OMV‐associated bacterial factors engage host innate immune receptors and couple vesicle association to inflammatory signaling remains poorly understood. Here, we investigated the contribution of OMV‐associated virulence factors and Toll‐like receptor 2 (TLR2) heterodimers to OMV–host cell interactions in gastric epithelial cells. Using engineered AGS and GES‐1 reporter cells expressing TLR2/1 or TLR2/6, together with genetically defined OMVs, we found that H. pylori OMVs preferentially associated with TLR2‐expressing cells and induced robust NF‐κB activation. Comparative analysis of OMVs from wild‐type and isogenic mutant strains identified Neutrophil‐Activating Protein A (NapA) as a major determinant of TLR2‐dependent OMV association and inflammatory signaling, whereas urease had a more limited contribution. Disruption of NapA or neutralization of TLR2 markedly reduced OMV association with gastric epithelial cells. Purified H. pylori lipopolysaccharide elicited a comparatively weak and TLR2/6‐biased response, indicating that it does not account for the robust TLR2‐dependent signaling induced by intact OMVs. Furthermore, OMV‐associated NapA exhibited greater pro‐inflammatory activity than soluble recombinant NapA, supporting a role for the vesicular context in enhancing TLR2‐dependent signaling. Pharmacological inhibition with sulforaphane significantly attenuated OMV‐induced TLR2/NF‐κB activation. Collectively, these findings identify a previously unrecognized role for OMV‐associated NapA in linking TLR2‐dependent vesicle association with gastric epithelial cells to inflammatory signaling and support a model in which vesicular presentation of bacterial factors contributes to innate immune receptor engagement, providing a mechanistic link between the initial OMV–host cell interaction and subsequent inflammatory signalling.
SN - 2001-3078
ER -